With the World Health Organization categorising diesel fumes as carcinogenic a Queensland University of Technology (QUT) scientist said if fumes had a stronger smell they would be easier to avoid.
QUT Public Health Associate Professor Adrian Barnett said most exhaust gasses were odourless and invisible as were some other very dangerous pollutants such as carbon monoxide, particulate matter and ozone.
"It is possible to give traffic pollution a smell and this has been demonstrated by some alternative fuels, such as chip fat," he said.
"Standard fuels could be given a smell by using an additive, such as methanol or butanol that smells after combustion.
"If traffic pollution smelled it might encourage policy changes to reduce exposure."
He said one easily fixable example was drive-throughs, where staff spend long hours next to idling engines, and often in enclosed spaces.
"The staff and their employers are probably unaware of their high exposure to traffic pollution. Adding a smell would change that and a simple solution would be for drivers to turn off idling engines.
"Turning off idling engines would also be beneficial in school pick-up zones, where lines of children, whose lungs are particularly vulnerable to traffic pollution, stand next to idling engines.
"If children, parents and schools were made aware of the problem of traffic pollution via a smell, many parents would turn off their engines."
Professor Barnett said knowing the dirtiest times and places would enable people to avoid exposure which was a key recommendation of an expert review on reducing the harms of traffic pollution.
"Exposure could be avoided by taking a different route to work, or jogging at a different time of the day."
He said a public that was more aware of the health effects of traffic pollution may be in favour of policy changes such as the development of pedestrian city centres and make them more wary of the planned locations of new roads.
"Many recently added or expanded roads in Brisbane are right next to hospitals and schools, two places where increasing traffic pollution will have a strong negative impact on health," he said.
"While the petrol and automotive industries are likely to argue that money would be better spent improving fuel and vehicle technology to reduce traffic pollution, the reality is that a completely clean vehicle fleet is 20 to 40 years away."
He said bold policy decisions such as banning smoking in pubs and proven successful in the past and such decisions were called for in relation to vehicle emissions.